This invention relates to the field of servicing of automatic transmissions for automobiles, and provides a device which substantially reduces the time required to adjust such transmissions, and also increases the accuracy of the adjustment. The invention can also be used in other fields.
In an automotive automatic transmission, it periodically becomes necessary to adjust the kickdown band. The kickdown band is a component which, when actuated by a hydraulically operated piston connected to a threaded pin, is pressed by the pin against a kickdown drum and stops the rotation of the drum. The kickdown band tends to wear after prolonged use, and it becomes necessary to adjust the position of the pin so that actuation of the piston will cause the kickdown band to move to the desired position.
Making the above adjustment, in the prior art, is difficult, because the various components are concentrically mounted in a cramped enclosure. Because the pin is threadedly connected to the piston, it is very difficult to adjust the pin while preventing the piston from rotating.
The prior art has attempted to solve the above problem by providing a spanner wrench which prevents the piston from rotating while the pin is adjusted. But the spanner wrench itself causes other problems. The handle of the spanner wrench is difficult to hold in the cramped environment surrounding the transmission. Moreover, to insure that the piston does not turn when the pin is being adjusted, it is necessary to mount the handle of the spanner wrench to the transmission casing, and this step makes the entire process more complex and unreliable. In some cases, the transmission casing may be damaged when using this prior art technique. Moreover, even when the spanner wrench is temporarily affixed to the transmission casing by a threaded connection, it is likely to disengage from the piston and often must be held by hand anyway.
The present invention solves the problems described above, by providing an apparatus and method which eliminate the need for the spanner wrench described above. The present invention substantially reduces the time required to adjust an automatic transmission, increases the accuracy of the adjustment, and reduces the likelihood of damage to the transmission casing, and bodily injury to the technician, while making the adjustment.